Chromium compounds of azo dyes



Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE HANS KKMMERER, OF

MANNHEIM, AND KARL HOLZAGH,

OF LUDWIGSHAFEN-ON-THE- RHINE, GERMANY. ASSIGNORS TO GENERAL ANILINE WORKS, INC., OF NEW YORK,

N. Y., A CORPORATION OF'DELAWARE CHBOMIUM COMPOUNDS 0]? A20 DYES No Drawing. Application filed February17, 1928, Serial No.

We have found that thedyestufis obtainable from o-hyclroxydiazo' compounds and.

QA-dihydroxyquinoline furnish complex chromium compounds of high commercial value. These chromium compounds may be produced, for example, by the action of solutions of chromium salts on the said di-hydroxyquinoline dyestuffs, with or without carrying out the operation at a pressure above atmospheric pressure. The resulting chromiferous dyestuffs are distinguished by their excellent fastness to washing, milling and light, and give red-brown, dark red, Bordeaux red or violet color shades according to the diazo components contained in the dyestuif. The dyeings may be discharged to a pure white with hydrosulphite and the dyestuffs are also suitable for printing on wool, silk and other fibers.

The following examples will further illustrate the nature of the said invention which however is not limited thereto. The parts are by weight.

Ewample 1 The azo dyestuif corresponding to the foris prepared from 223 parts of diazotized 4- chlor-2-amino-phenol-6-sulfonic acid and 195 parts of QA-dihydroxyquinoline in any known or suitable manner and, after filtration, is stirred with 8000 parts of water in an enamelled pressure resisting vessel and heated at from 110. to 120 C. for 1 hours with 120 parts of chromium oxid and 270 parts of an 85 per cent solution of formic acid. The finished chromium compound is salted out, dissolved in 500 parts of water containing 140 parts of40 Be. caustic soda solution and reprecipitated with common sa t. stuff is filtered, pressed and dried. The dyestufi is in the form of a dark red powder,

bronzy vcrystals the dyestuff is The resulting sodium salt of the dye 255,177, and in Germany August 6, 1925.

which dissolves to a brownish-orange solution in sulfuric acid, and to a cherry red solution in water. The free acid of the dyestulf may be obtained in the form of small from the dilute alcoholic solution of the sodium salt by treatment with hydrochloric acid. a

.011 wool, the dyestuif gives Bordeauxred dyeings in an acid bath, which are very fast to washing, milling and light.

Example 2 383 parts of the sodium salt of the azo dyestuff corresponding to the formula:

and obtainable from diazotized Q-aminophenoli-sulfonic :acid and ZA-dihydroxyquinoline are stirred with 7000 parts of water and. mixed with a solution of chromium formate which corresponds to 80 parts by weight of chromium oxid. The mixture is heated in an. enamelled pressure tight vessel for from l to 2 hours to about 120 (land then cooled. The finished chromium compound of salted out and filtered whereupon it is converted into the readily soluble sodium salt by treating it with soda or caustic soda solution, and recovered as described in Example 1. The new dyestuif obtainedis a brownish powder which dissolves water dark red shades from an acid bath.

The complex chromiumcompound of the dyestulf corresponding to theformula:

OaH

chlor-2-aminophenoll-sulfonic acid and 2.4- dihydroxyquinoline dyes orange red shades on wool.

Example 3 428 parts of the sodium salt of the dyestufi corresponding to the formula:

and obtainable from diazotized 4-nitro-2- aminophenol-ti-sulfonic acid and 2.4l-dihydroxyquinoline are heated in a closed vessel with 8000 parts of water and a solution of 100 parts of chromium oxid and 230 parts of per cent formic acid in boiling water for from 2 to 3 hours to from 110 to 120 C. After that time the mixture is cooled and the separation of the dyestuff is completed by adding common salt. The product is filtered off and converted into its sodium salt as is described in Example 1. The red powder obtained dissolves readily in water to a yellow red solution which color is changed to red by adding a mineral acid. The new dyestufl dyes wool very even and bright red shades which are excellently fast to light and washing.

The chromium compound of the azo dyec. stuff obtainable from 6-nitro-2-aminophenol- 4l-sulfonic acid and 2.4L-dihydroxyquinoline and corresponding to the formula:

prepared in an analogous manner dyes wool red shades with a more bluish tinge and of similar properties as regards fastness.

This application is a continuation in part of our copending application Ser. No. 124,776, filed July 24, 1926, in which we have generically shown that it is of great advantage to produce chromium compounds of ohydroxy-azo dyestuffs by carrying out the chromation under elevated pressure.

lVhat we claim is:

1. As new articles of manufacture the chromium compounds of the o-hydroxyazo dyestuffs obtainable from o-hydroxydiazo compounds and 2.4-dihydroXyquinoline dyeing very fast red to brown and violet shades.

2. As a new article of manufacture the chromium compound of the o-hydroxyazo dyestuif obtainable from diazotized 4-chlor0- 2-aminophenol-6-sulfonic acid and 2.4l-dihydroxyquinoline corresponding to the formula:

HANS KAMMERER. KARL HOLZAGH. 

